Outdoors

Rare native plants thrive in North Shore ravines

June 25, 2009|By Barbara Brotman

Searching for a beautiful and fragile natural habitat for a nice eco-tourism jaunt? If you can't make it to a rain forest, consider the ravines of the North Shore.

A defining geological feature of the north suburban lakefront, the ravines do far more than put scenic curves onto Sheridan Road. Their unique microclimate makes them home to plants that live nowhere else in the Chicago area.

"Some of the rarest plants in Illinois are located in these ravines," said Ken Klick, a botanist who is restoration ecologist with the Lake County Forest Preserves.

Beyond their ecological value, the ravines make for awesome scenery.

"It's not the Grand Canyon, but it's splendid," said Robert Megquier, director of land preservation at Openlands, which plans to open one of its ravines to the public in September. "It's a unique part of the Illinois landscape to have 70-foot-high cliffs overlooking Lake Michigan. ... When you get up in these ravines, the views are dramatic."

The vistas are courtesy of the area's last glacier. When it receded some 12,000 years ago, it left behind a high moraine bluff above the lake north of Chicago. The lake bed was 100 feet lower than it is today, said Klick. Water had to get from the high moraine down to the lake. It did so by cutting ravines into the moraine.

Most of the 30-odd ravines between Evanston and the Wisconsin are privately owned. But there are ravines in four lakefront parks in Highland Park. Openlands, a conservation group, owns three ravines on its Lakeshore Preserve south of Ft. Sheridan.

And at the Ft. Sheridan Forest Preserve, the Lake County Forest Preserves owns two ravines and part-owns a third.

You can take a trail alongside Hutchinson Ravine at Ft. Sheridan. The ravine itself is so fragile and steep after the wet spring that visitors are asked to keep to the trail. But from there, you can look into the ravine, shaded and dotted with wildflowers like wild geranium, Solomon's seal and trillium.

But evidence of the ravines' unique nature can be found in the trees and shrubs. They include paper birches, white cedar buffaloberry and spreading juniper -- plants that are commonly found in Wisconsin or Canada, but not this far south.

The ravines are noticeably chillier than the land around them. Cooled by their proximity to Lake Michigan, they are slices of the North Woods plunked down outside Chicago.

The ravines sweep lake-cooled air in and up, lowering their temperature even further. "The wind ... will come off the lake and rise through the ravines," said Megquier, who is overseeing Openlands' ravine restoration. "There are times you can physically feel it. You can descend down into the ravine and it's 10 degrees cooler."

And in winter, the ravines get lake-effect snow, which blankets plants and protects them from freeze/thaw cycles. That allows some sedges, grasses and rhododendron-related plants to survive here.

The result is a distinctive microclimate that provides habitat for rare and endangered plants like the oak fern, which is on the regionally rare list.

"You get a mix of flora that's a little bit more like northern Wisconsin, sort of a glacial ice age remnant," said Rebecca Grill, natural areas coordinator for the Park District of Highland Park.

The ravines are also living laboratories of native plants. A remarkable number of wildflower seeds are still present in the soil, said Megquier, providing a store of native seeds that is priceless. "Once you lose the native seed bank, it's lost forever," he said.

But many of the ravines have been severely eroded. As surrounding land has been paved over, Klick said, water runoff can no longer be absorbed by soil. It makes its way to the ravines instead, where it gushes down in high volumes, making them ever steeper. And the ravines themselves have lost much of the vegetation that used to help absorb and filter runoff.

The Lake County Forest Preserves spent a year and more than $1 million repairing the side slopes of the ravines, stabilizing their bottoms, planting native trees and shrubs, seeding the slopes with 30 species of wildflowers and creating swales to absorb water runoff. It is now starting work on nearby Jane Ravine (the fort's ravines are named after men with connections to its history).

Openlands expects to spend $4 million on its ravines and bluffs. "It's interesting -- it's an ecosystem we don't know a lot about," Megquier said. "We've gotten pretty good at restoring woodlands and savannas, [but] this is pioneering work, restoring ravines."

Visit one, and let it restore you.

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IF YOU GO

To take the Hutchinson Ravine trail, enter Ft. Sheridan Forest Preserve at Old Elm Road, bear left into the town of Ft. Sheridan, then turn left on Gilgare Lane. Park in the lot next to the trail. For more information, visit tiny.cc/iZ8QH.

In Highland Park, there are ravines at Rosewood, Millard, Moraine and Central Parks. Trees usually found in more northern climates can be seen at Central and Millard Parks. At Rosewood Park, you can walk a path down the slope of the ravine. For a map of the parks, visit tiny.cc/6eoCS.

Openlands plans to open Bartlett Ravine, south of Ft. Sheridan, in mid-September. For more information and an interactive map of the ravines of Openlands' Lakeshore Preserve and the Ft. Sheridan Forest Preserve, visit tiny.cc/JckhM.